Hamels gave up three runs on six hits and four walks over five innings against the Nationals on Friday while showing diminished velocity. While he told reporters following the game that he didn’t feel any pain, Phillies manager Charlie Manuel said the left-hander experienced some stiffness in his shoulder.

The Phillies were rained out yesterday and have an off-day tonight, so they could push Hamels back in the rotation even if the MRI doesn’t reveal anything serious.

Hamels, 27, is 13-7 with a 2.62 ERA and 155/35 K/BB ratio over 25 starts this season. He ranks third in the National League with 172 innings pitched.